Wilbur f



(No Model.)

W. P. DIAL. SEAM TRIMMER FOR SEWING MAOHINES. No. 466,272. Patented Dec. 29, 1891-.

b/0 V pAh UNITED STATES ATENT OFFICE.

TVILBUR F. DIAL, OF BRIDGEPORT, CONN ECTICUT, ASSIGNOR TO THE WHEELER & WILSON MANUFACTURING COMPANY,

PLACE.

on SAME SEAM-TRIMMER FOR SEWING-MACHINES.

SPECIFICATION forming part of Letters Patent No. 466,272, dated December 29, 1891.

Q Application filed May 18, 1891- Serial No. 393,147. (No model.)

To all whom it may concern.-

Be'it known that I, WILBUR F. DIAL, of Bridgeport, county of Fairfield, State of Connecticut, have invented an Improvement in Seam Trimmers for Sewing Machines, of which the following description, in connection with the accompanyingv drawings, is a specification,like letters on the drawings representing like parts.

This invention, relating to seam-trimming mechanism for sewing-machines, has for its object more especially to improve that class of trimming mechanism wherein a blade or knife is carried by a vertically movable or reciprocating bar contained in the head of the overhanging arm of the machine, the ob-' ject of this present invention being to impart to the said blade or knife a drawing out, such a out being much more efficient than a plunging cut, and also more efficient than a cut made'bya diagonal edge of avertically-movable blade.

My invention consists in the combination, with a suitable stitch-forming mechanism, of

a vertically and laterally movable knife-V shows in full lines the blade as it commences to cut, the dotted lines showing the sliding movement given to the blade; Fig. 5, a righthand-edge view of the blade shown in Fig. 4:, and Fig. 6 shows a modification to be described.

The bed A, overhanging arm A, shaft A needle-bar A actuated by a link connected to said shaft, the presser-foot A, and its shank A are and may be all as usual.

The blade at is connected to the lower end of a blade-carrier a, herein represented as a flat bar having itsfulcrum upon a stud a the stud entering, as represented, a slot a in the bar, the stud forming a fulcrum for the blade-carrier. The blade-carrier is reciprocated in this instance of my invention by means ofapin or device 6 at the end of a rocking arm I) of a rock-shaft 12 To rock the blade-carrier in order that the blade may have a lateral movement as it enters the material in its descent, I have provided a rocking device which in the embodiment of my invention shown in Fig. 1 is represented as a stud d entering a slot (1 of the said-bar, the inclination of the slot more or less controlling the extent of lateral movement of the blade while cutting the material. The slot referred to is angular with relation to the line of reciprocation of the blade-carrier, so that as the blade carrier reciprocates it is also rocked,

and the greater the inclination of the slot the greater the rocking movement.

The slot d and stud d constitute a simple rocking device for the lever; but Imay instead use any other suitable rocking means to impart to the blade-carrier a rocking movement during each cutting operation, this invention not being limited to the particular construction of the rocking device, for prior to this invention I am not aware that a vertically-reciprocating blade-carrier has ever had a rocking movement during the trimmingstroke to cause the vertically-reciprocating blade to move laterally in contact with the material to act with a draw out.

As an equivalent for the slot and stud I may employ a short link it, represented in Fig. 6 as pivoted at n to the blade-carrier and at n to the frame of the machine.

The rock-shaft b loosely fitted into its bearings b 22 has at its rear end an arm I), provided with a suitable'roller or other stud b which enters, as herein shown, a groove Z2 in the balance or hand wheel Z9 The rock-shaft b has a collar b, against which acts one end of'a spiral spring 12 the said spring acting at its other end against the bearing 12 normally keeping the roller or other stud b in the cam-grooveb but when it is desired to suspend the operation of the cutter, the operator will engage the stud b at the end of the arm b and pull the rock-shaft to the right, thus withdrawing the roller-stud from its actuating-groove, and then by moving the pin in an upward direction the bar a may be elevated for a greater distance than when in regular operation, and in so doing the inclined portion 15 of the lower part of the slot (1 by acting on the fulcrum-stud a causes the lower end of the bar a to be thrown to the left, away from the needle-bar.

It is not intended to limit this invention to the exact devices shown for actuating the rocking shaft b 1 am aware that blades or cutters have been connected to the lower end of vertically-reoiprocatin g bars of many different shapes; but I am not aware that a vertically-reciprocatin g bar has ever had combined with it any device by which to vibrate the bar while the blade is in contact with and cutting the material to thus make a draw cut, and in my invention the draw of the cut is in the same general direction as the feed, so that the cut produces the least possible strain on the material.

I am aware that a Vertically-reciprocating bar has been employed to which the knife is jointed, a pin on the lower end of the knife working in a slot beneath the bed-plate, and I am also aware that the lower end of a knife so jointed to the bar has been connected by a link to an ear beneath the bed-plate; but such constructions I do not claim.

I am aware that a vertically-reciprocating cutter-carrying bar having a blade or knife rigidly attached thereto has been employed, the said bar having slots therein parallel to the line of reciprocation, fixed pins entering said slots and guiding said bar in its straight up and down reciprocations, as in United States Patent No. 212,122; but such construetion I do not claim.

I claim In a seam-trimming apparatus, a cuttercarrying bar, a blade or knife rigidly attached thereto, means to reciprocate the said bar vertically, and a fulcrum for said bar and on which it slides, combined with a guide for said bar located angularly with relation to the line of reciprocation of the bar, to rock the same upon its fulcrum and carry the knife bodily in the direction of the feeding movement of the material while said knife is descending, to thereby cut the material in the direction of the progress of the seam, substantially as described.

In testimony whereof I have signed in y name to this specification in the presence of two subscribing witnesses.

WILBUR F. DIAL.

Witnesses:

GEO. W. GREGORY, ISAAC IIOLDEN. 

